This is the result of a bug in the Apache header files (reported Sep 1999, PR# 5012, but never fixed).

The problem is due to the fact that httpd was compiled with optimization and ap_os_is_path_absolute() was
inlined, but when mod_fastcgi.so was compiled optimization was not enabled and ap_os_is_path_absolute() was
expected to be an external symbol.

Try this apxs invocation instead (it will turn on optimization and inline ap_os_is_path_apsolute()):